docs: def pkgconfig(*packages, **kw):
      """Based on http://code.activestate.com/recipes/502261-python-distutils-pkg-config/#c2"""
  
      flag_map = {'-I': 'include_dirs', '-L': 'library_dirs', '-l': 'libraries'}
      output = sp.Popen(["pkg-config", "--libs", "--cflags"] + list(packages),
                        stdout=sp.PIPE).communicate()[0]
      if six.PY3:
          output = output.decode('utf8')
      for token in output.split():
          if token[:2] in flag_map:
              kw.setdefault(flag_map.get(token[:2]), []).append(token[2:])
          else:
              kw.setdefault('extra_compile_args', []).append(token)
  
      kw['include_dirs'] += [np.get_include()]
  
      return kw